分层开采底分层大断面切眼对棚支护技术

Application of Double Joist Steel Shed Support Technology in Large Section Open-off Cut of the Lower Slice

厚煤层分层开采中,底分层回采巷道的顶板是上分层工作面的冒落矸石或受顶分层采动影响的破碎顶煤,不宜采用锚杆锚索联合支护,多数情况下需要采用工字钢棚梁配合单体液压支柱的架棚支护方式来维护巷道,特别是断面尺寸较大的切眼支护往往成为底分层回采设计的难题之一。以中煤能源新疆某矿底分层大断面切眼支护为例,依据压力拱理论计算得出了人工支护结构的荷载集度,在此基础上,以棚梁工字钢达到屈服强度为标准,确定了工字钢架棚的合理排距,为现场设计和施工提供了参考依据。

During the layer mining process of the thick coal seam,the roof at the lower layer generally are the caving gangues of the upper layer working face and the crushed coal falling from the upper roof affected by the upper mining disturbance,so it is unsuitable to use the combined support of bolt and cable. In most cases,the shed support with the combined single hydraulic prop is adopted to maintain the roadway stability. Especially,the open-off cut supporting with large section becomes one of the difficulties in the lower layer design. With a large section open-off cut support in Xinjiang under China Coal Energy as a case,the load concentration of artificial support structure is calculated out,according to the pressure arch theory. On this basis,the reasonable array distance of the I-steel shed beam support is determined when the I-steel shed beam reaches the standard yield strength. These provide a reference for field design and construction of the shed.